Anyone familiar with these vintage touchscreens?

Judging by the year, it was probably a teletext terminal. There were various field trials of such systems around that era.? We had one in Toronto's Eaton Centre - it was based on NAPLPS, and used a PDP11/23. There was a lot of Canadian Government money put into research to promote he Canadian vector-based protocol, claimed to be more efficient than the European alpha-mosaic ones.? Ours ran at 1200/150(?) baud. Research was done at a Bell Canada site on Carlingview Avenue in Ottawa under some sort of sub-contract.?? They used Able DMAXes on an 11/70 which had a pot to adjust the 150 baud clock.? They actually flew me up from Toronto, with a scope, to adjust that pot, since everybody there was hands-off this external stuff. It may have had a future if HTTP and the internet were not just around the corner:-)